Numerical Analysis of Stator Inter-turn Fault and Demagnetization effect on a BLDC Motor using Electromagnetic Signatures

Abstract

Among various available faults in Brushless Direct Current (BLDC) motors, Stator Inter-turn Fault (SITF) in the stator and demagnetization of Permanent Magnets (PMs) in the rotor are more recurrent. The main cause of SITF is the breakdown of insulation between the windings which leads to the heavy flow of inrush currents damaging the stator windings. The consequent outcome of SITF further stimulates in demagnetization of PMs in the machine. The existence of faults in the motor adversely affect the performance of the machine by bringing change in the machine quantities like phase currents, back-EMF, electromagnetic torque, mechanical speed and magnetic flux density & flux lines. The Maxwe11-2D model for a BLDC motor is developed using Numerical Methods (NMs) like Finite Element (FE) modeling tool and further the effect of SITF and demagnetization faults are induced in them. The electric drive system of the motor is modeled in a mathematical Simplorer tool, which is further co-simulated with the FE developed model. The performance of the machine is investigated under both healthy and fault conditions. The significant detectable changes in the machine’s electromagnetic quantities shall draw inference to distinguish between the two types of respective faults.